Mars Express

What is ESA’s Mars Express?

Mars Express is the European Space Agency’s first mission to Mars, an orbiterOrbiterAn orbiter circles Mars without landing, studying the planet from above — and many also relay rover data back to Earth.More in the glossary that has studied the planet, its air and its two moons since Dec 25, 2003.[1][2] It launched on Jun 2, 2003, on a Soyuz-Fregat rocket from Baikonur, Kazakhstan, and reached Mars just over six months later.[2][5] ESA calls it the first planetary mission operated entirely by Europe.[5]

The name comes from how fast it was built. Design and development took about five years, compared with about ten for similar missions.[5] It reused equipment from ESA’s Rosetta comet mission, and some of its instruments descend from Russia’s 1996 Mars mission.[2]

It was designed to work for one Mars yearMars YearA Mars year lasts 687 Earth days (about 669 sols), and scientists number them from Mars Year 1, which began on April 11, 1955.More in the glossary, 687 Earth days. It is now in its third decade.[7][21] Only NASA’s Mars Odyssey, at Mars since 2001, has been working there longer.[24][27]

ESA figures, as of the dates shown. ESA gives the launch mass as 1,120 kg on its mission page and 1,108 kg on its launcher page.[1][4][3][24][7][20][23]

What happened to Beagle 2?

Beagle 2, a small British landerLanderA lander touches down on Mars and works from one spot, unlike a rover, which drives.More in the glossary carried by Mars Express, reached the surface on Dec 25, 2003, but never called home.[8][10] Mars Express released it on Dec 19, 2003, six days before arrival.[8] Mars Express, NASA’s Mars Odyssey and telescopes on Earth all listened and heard nothing. On Feb 6, 2004, the Beagle 2 Management Board declared it lost.[2]

The mystery ended on Jan 16, 2015. Images from the HiRISE camera on NASA’s Mars Reconnaissance Orbiter showed Beagle 2 in Isidis Planitia, about 5 km (3 mi) from the center of its target area.[8][9] Michael Croon, a former member of the Mars Express operations team, first searched the images.[8][9] Only one, two or at most three of the lander’s four solar panels had opened. Its radio antenna stayed covered, so no signal could get out.[8][10] At less than 2 m (7 ft) across, Beagle 2 was at the limit of what HiRISE can see.[9]

What instruments does Mars Express carry?

ESA lists eight: seven science instruments from launch, plus a small camera that became a science instrument in 2016.[6][7]

• 01HRSC, the High Resolution Stereo Camera. Takes color and 3D pictures at about 10 m (33 ft) per pixel, with chosen spots at 2 m (7 ft).[2][6] It comes from the German Aerospace Center, DLR.[21]
• 02MARSIS, a radar. Its 40 m (130 ft) antenna sends radio waves a few kilometers into the ground.[6] It was the first radar sounder to orbit another planet, developed in Italy with NASA’s JPL.[11]
• 03OMEGA, a mineral mapper. Reads visible and infrared light from the surface to map minerals.[6] One of its first finds was water ice exposed in the polar caps.[21]
• 04SPICAM and PFS, two spectrometers. They track ozone, water vapor, carbon monoxide and temperature in the air. PFS also looks for trace gases such as methane.[6]
• 05ASPERA-3 and MaRS. ASPERA-3 measures particles in the upper atmosphere to see how the solar wind strips it away. MaRS uses the spacecraft’s own radio signal to probe the atmosphere and Mars’s gravity.[6]
• 06VMC, the “Mars webcam.” Fitted to confirm that Beagle 2 had separated, then turned into a science camera.[6]

What has Mars Express found?

Mostly water: minerals that only form in water, buried ice, and a long argument about liquid water under the south pole.[2][15]

• 01Minerals made by water. With NASA’s CRISM, OMEGA data went into a 2022 map of water-altered minerals such as clays and salts. A decade earlier, about 1,000 outcrops were known. The map shows hundreds of thousands, across the planet’s oldest ground.[16]
• 02Ice at the south pole. In 2007 the MARSIS team reported that the south polar layered deposits hold enough water to cover the whole planet about 11 m (36 ft) deep.[17] More on water on Mars.
• 03Methane, maybe. In 2004 PFS reported about 10 parts per billion of methane in the air. The far more sensitive Trace Gas Orbiter has found none.[19]
• 04An aurora. On Aug 11, 2004, SPICAM recorded the first aurora seen at Mars: a glow about 30 km (19 mi) across, over a patch of magnetized crust.[18]
• 05Inside Phobos. On Dec 29, 2013, Mars Express passed 45 km (28 mi) from Phobos to measure its gravity. Earlier flybys suggested the moon could be a quarter to a third empty space.[20][7]

Is there a lake under Mars’s south pole?

Probably not, though the question is still debated.[13][14] In July 2018 the MARSIS team reported a bright radar echo about 1.5 km (0.9 mi) under the south polar ice, in a zone about 20 km (12 mi) wide. They interpreted it as a pond of salty liquid water.[11] In 2020, with more data, they reported three more ponds. ESA said the largest was about 20 by 30 km (12 by 19 mi).[12] ESA still lists the find among the mission’s highlights.[15]

Other scientists doubted it. In 2021 NASA reported on three studies that cast doubt on the lakes; some scientists now thought clays, not water, might be making the bright echoes.[13] On May 26, 2025, NASA’s Mars Reconnaissance Orbiter rolled 120 degrees to aim its SHARAD radar at the spot. It picked up only a faint signal. Its team reported in November 2025 that the feature is more likely rock and dust, perhaps an old lava flow. “While this new data won’t settle the debate, it makes it very hard to support the idea of a liquid water lake,” said Gareth Morgan of the Planetary Science Institute.[14]

What is the Mars webcam?

It is the Visual Monitoring Camera (VMC), a small camera fitted to watch Beagle 2 leave, which ESA now uses for science and to share views of Mars.[6] ESA calls it the “Mars webcam” because its pictures are like those of a home webcam from 2003.[29] Since 2007 it has been used to share pictures, and in 2016 ESA began turning it into a science camera that tracks clouds, dust and frost. Its images are processed automatically and posted to Flickr soon after they reach Earth.[6]

On Jun 2, 2023, the 20th anniversary of launch, ESA streamed VMC pictures for an hour, one about every 50 seconds. It was ESA’s first Mars livestream, “as close to real-time as the speed of light would allow.” Rain at the ground station in Cebreros, Spain, cut the feed for part of the hour.[22] See Is there a live feed from Mars?

Is Mars Express still working?

Yes. In June 2026 ESA’s member states endorsed another extension for Mars Express, one of 13 science missions extended at the meeting.[25] ESA’s announcement didn’t give a new end date. The previous extension, agreed in 2023, ran science to the end of 2026, with an indicative extension to Dec 31, 2028, to support Japan’s MMX mission to Phobos.[26] The team’s proposal covered 2027 to 2029.[27] In September 2026 ESA published new HRSC pictures of a purple-tinted ice cliff near the south pole.[28]

• 01Fuel and batteries. The mission team said in 2026 that it has fuel for operations until at least 2033, and batteries good until 2042.[27]
• 02No gyroscopes needed. In 2018 Mars Express became ESA’s first spacecraft to fly “gyroless,” steering by its star trackers. ESA said this could add about 10 years to its life.[21] It now has three working gyroscopes, the minimum it needs.[27]
• 03Instruments. The team says every instrument still works as needed, except PFS, which loses data at times because a laser is aging.[27]
• 04A backup relay. Mars Express has relayed data for seven landers and rovers, starting with NASA’s Spirit in 2004.[23] NASA lists it as a backup in today’s Mars Relay Network.[24]

Mission timeline

1. Jun 2, 2003Launches from Baikonur on a Soyuz-Fregat rocket.[2]
2. Dec 19, 2003Releases the Beagle 2 lander.[8]
3. Dec 25, 2003Enters orbit around Mars. Beagle 2 lands but is never heard from.[3][8]
4. Feb 6, 2004Beagle 2 is declared lost.[2]
5. Aug 11, 2004SPICAM records the first aurora seen at Mars.[18]
6. Dec 29, 2013Passes 45 km from Phobos, its closest flyby.[20][7]
7. Jan 16, 2015Beagle 2 is found in HiRISE images.[8][9]
8. May 2018Starts routine flying without gyroscopes.[27]
9. Jul 25, 2018The MARSIS team reports a possible lake under the south pole.[11]
10. Jun 2, 2023ESA’s first livestream from Mars.[22]
11. Nov 25, 2025NASA reports a radar result that makes the lake “very hard to support.”[14]
12. Jun 11, 2026ESA announces another extension.[25]

Sources

1. ESA — Mars ExpressPrimary · checked Oct 6, 2026
2. ESA — Mars Express overviewPrimary · checked Oct 6, 2026
3. ESA — The missionPrimary · checked Oct 6, 2026
4. ESA — The launcherPrimary · checked Oct 6, 2026
5. ESA — Mars Express Frequently Asked Questions (FAQs)Primary · checked Oct 6, 2026
6. ESA — Mars Express orbiter instrumentsPrimary · checked Oct 6, 2026
7. ESA — 20 years and counting: Mars Express in numbersPrimary · checked Oct 6, 2026
8. ESA Science & Technology — Beagle-2 lander found on MarsPrimary · checked Oct 6, 2026
9. NASA JPL — ‘Lost’ 2003 Mars Lander Found by Mars Reconnaissance OrbiterPrimary · checked Oct 6, 2026
10. UK Space Agency (GOV.UK) — UK-led Beagle 2 lander found on MarsPrimary · checked Oct 6, 2026
11. ESA — Mars Express detects liquid water hidden under planet’s south polePrimary · checked Oct 6, 2026
12. ESA — Mars Express finds more underground water on MarsPrimary · checked Oct 6, 2026
13. NASA JPL — Clays, Not Water, Are Likely Source of Mars ‘Lakes’Primary · checked Oct 6, 2026
14. NASA JPL — NASA Orbiter Shines New Light on Long-Running Martian MysteryPrimary · checked Oct 6, 2026
15. ESA — Mars Express science highlightsPrimary · checked Oct 6, 2026
16. ESA — New water map of Mars will prove invaluable for future explorationPrimary · checked Oct 6, 2026
17. ESA — Mars Express radar gauges water quantity around Mars’ south polePrimary · checked Oct 6, 2026
18. ESA — Mars Express discovers aurorae on MarsPrimary · checked Oct 6, 2026
19. ESA — First results from the ExoMars Trace Gas OrbiterPrimary · checked Oct 6, 2026
20. ESA — Mars Express heading towards daring flyby of PhobosPrimary · checked Oct 6, 2026
21. ESA — Mars Express milestones: two-year mission enters third decadePrimary · checked Oct 6, 2026
22. ESA — First Mars livestream: the moviePrimary · checked Oct 6, 2026
23. ESA — Mars Express sets data relay recordPrimary · checked Oct 6, 2026
24. NASA Science — Mars Relay NetworkPrimary · checked Oct 6, 2026
25. ESA — ESA science missions get green light for new discoveriesPrimary · checked Oct 6, 2026
26. ESA Science & Technology — Extended life for ESA’s science missionsPrimary · checked Oct 6, 2026
27. Europlanet Science Congress 2026 (abstract by ESA’s Mars Express team) — Mars Express: One more extension to foster its legacy (EPSC2026-1142)Primary · checked Oct 6, 2026
28. ESA — Purple swirls on the Red PlanetPrimary · checked Oct 6, 2026
29. ESA — The Visual Monitoring Camera on board Mars Express: ESA’s ‘Mars webcam’Primary · checked Oct 6, 2026